1 /*******************************************************************************
2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2008 Daniel Le Berre
3 *
4 * All rights reserved. This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License v1.0
6 * which accompanies this distribution, and is available at
7 * http://www.eclipse.org/legal/epl-v10.html
8 *
9 * Alternatively, the contents of this file may be used under the terms of
10 * either the GNU Lesser General Public License Version 2.1 or later (the
11 * "LGPL"), in which case the provisions of the LGPL are applicable instead
12 * of those above. If you wish to allow use of your version of this file only
13 * under the terms of the LGPL, and not to allow others to use your version of
14 * this file under the terms of the EPL, indicate your decision by deleting
15 * the provisions above and replace them with the notice and other provisions
16 * required by the LGPL. If you do not delete the provisions above, a recipient
17 * may use your version of this file under the terms of the EPL or the LGPL.
18 *
19 * Based on the original MiniSat specification from:
20 *
21 * An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the
22 * Sixth International Conference on Theory and Applications of Satisfiability
23 * Testing, LNCS 2919, pp 502-518, 2003.
24 *
25 * See www.minisat.se for the original solver in C++.
26 *
27 *******************************************************************************/
28 package org.sat4j.minisat.constraints;
29
30 import org.sat4j.minisat.constraints.card.AtLeast;
31 import org.sat4j.minisat.constraints.cnf.Clauses;
32 import org.sat4j.minisat.constraints.cnf.LearntBinaryClause;
33 import org.sat4j.minisat.constraints.cnf.LearntHTClause;
34 import org.sat4j.minisat.constraints.cnf.Lits;
35 import org.sat4j.minisat.constraints.cnf.OriginalBinaryClause;
36 import org.sat4j.minisat.constraints.cnf.OriginalHTClause;
37 import org.sat4j.minisat.constraints.cnf.UnitClause;
38 import org.sat4j.minisat.core.Constr;
39 import org.sat4j.minisat.core.ILits;
40 import org.sat4j.specs.ContradictionException;
41 import org.sat4j.specs.IVecInt;
42
43 /**
44 * Uses specific data structure for cardinality constraints.
45 *
46 * @author leberre
47 * @since 2.1
48 */
49 public class MixedDataStructureDanielHT extends AbstractDataStructureFactory {
50
51 private static final long serialVersionUID = 1L;
52
53 /*
54 * (non-Javadoc)
55 *
56 * @see
57 * org.sat4j.minisat.DataStructureFactory#createCardinalityConstraint(org
58 * .sat4j.datatype.VecInt, int)
59 */
60 @Override
61 public Constr createCardinalityConstraint(IVecInt literals, int degree)
62 throws ContradictionException {
63 return AtLeast.atLeastNew(solver, getVocabulary(), literals, degree);
64 }
65
66 /*
67 * (non-Javadoc)
68 *
69 * @see
70 * org.sat4j.minisat.DataStructureFactory#createClause(org.sat4j.datatype
71 * .VecInt)
72 */
73 public Constr createClause(IVecInt literals) throws ContradictionException {
74 IVecInt v = Clauses.sanityCheck(literals, getVocabulary(), solver);
75 if (v == null) {
76 // tautological clause
77 return null;
78 }
79 if (v.size() == 1) {
80 return new UnitClause(v.last());
81 }
82 if (v.size() == 2) {
83 return OriginalBinaryClause.brandNewClause(solver, getVocabulary(),
84 v);
85 }
86 return OriginalHTClause.brandNewClause(solver, getVocabulary(), v);
87 }
88
89 public Constr createUnregisteredClause(IVecInt literals) {
90 if (literals.size() == 1) {
91 return new UnitClause(literals.last());
92 }
93 if (literals.size() == 2) {
94 return new LearntBinaryClause(literals, getVocabulary());
95 }
96 return new LearntHTClause(literals, getVocabulary());
97 }
98
99 @Override
100 protected ILits createLits() {
101 return new Lits();
102 }
103 }